Over the years, many systems for simulating virtual reality experiences have been developed to facilitate training, as well as provide entertainment. Simulation systems can be operated by persons desirous of experiencing particular endeavors, by manipulating conventional controls, to be shown the results of their actions as by simulated displays. For example, in training activities, simulators are widely used to provide experience in airplanes, helicopters, ground vehicles and so on. More recently, simulators for entertaining and educating children and adults alike, in sport exercises and the like, have gained tremendous popularity.
To that end, current state of the art technology used in creating simulation systems typically involves a visual display. Thus, as the person operating the simulation system manipulates the controls of the system, he or she is provided with a responsive display showing his or her view, as the simulator simulates movement through a programmed environment. Contemporary simulators utilize advanced computer graphics techniques to provide a dynamic display. An environment is programmed and positional signals are developed to indicate the position and orientation of the simulated vehicle in the environment. Representative simulator data is subsequently supplied to a computer graphics system to attain a dynamic display.
Consider the sport of hang gliding as one example, where persons may desire to experience the thrill of the sport without being exposed to the actual dangers of participating in the sport. Recent methods of flight simulation, relating to light aircrafts including hang gliders, for people in search of the eternal thrill of flying, employ digital microprocessors or computers and accompanying software programming. There are several commercially available flight simulation software packages, which can be run on personal computers. For example, Microsoft's "Flight Simulator.RTM.," version 4.0 includes a sailplane simulation. Microsoft's "Aircraft and Scenery Designer," version 1.0 can be used to modify the sailplane flight characteristics so that it accurately simulates hang glider performance.
Different landscapes and environments can be created using the scenery design portion of the software, providing a means for creation of various flying sites and situations. Several computer peripheral devices such as joysticks, yokes, rudder pedals or the like, are typically used to provide input for the computer based simulators.
However, none of these simulation packages provide a real-time virtual reality experience of suspended flight.
Turning now to display systems utilized in current simulation systems, it should be recognized that large screen displays have the capability of operating in real-time at high resolution rates to provide three-dimensional images of video information. Generally, stereoscopic imaging capability enhances displays, by portraying data containing altitude, distance and ocean depth information in conjunction with other inter-related operational parameters.
The stereoscopic imaging process has two fundamental requirements. First, two distinct and different images must be presented to the viewer, each of which presents the scene from the view point of one of the viewer's eyes. Next, the system must be able to assure that each eye sees only the one view intended for it, that is, the images must be separated, one to each eye. Stereoscopic image separation is generally performed by any one four methods: (1) Optical separation (using lenses, prisms, mirrors etc.), (2) Color separation (anaglyphs), (3) Temporal separation (using shutters, etc.) and (4) Polarization separation (using polaroid filters).
Of these, the most amenable to large screen projection systems has traditionally been the polarization technique. However, the polarization technique requires that the two images be projected with orthogonal polarizations, and that the viewer wear a pair of polaroid glasses whose polarization axes are arranged at right angles to one another.
Color separation relies upon encoding the left and right images, such that the left eye and the right eye images are portrayed in colors and such that the viewer sees two different color images. This makes it difficult to portray full color images, produces eye fatigue through color bombardment, which in turn desensitizes the visual system with respect to the colors involved and creates problems for ambient viewing.
Temporal separation requires the viewer to wear eyeglasses attached to the video system with a cord and is often accompanied by high voltages in the eyeglasses.
Optical separation has thus far required bulky, often elaborate optical apparatus between the screen and the observer to separate the images.
Achieving a realistic visual display can be an expensive undertaking, which is not always practical, particularly for entertainment simulators. Thus, a need exists for improved and inexpensive techniques for providing more realistic virtual reality experiences and simulated displays.
The present invention is directed to a simulation system for simulating virtual reality experiences with a stereoscopic and collimated virtual image display, which utilizes a unique and inexpensive optical separation technique for providing "pupil forming" simulated images to a person at a fixed point of reference relative to the stereoscopic and collimated virtual image display. In accordance with the disclosed embodiment, the simulation system of the present invention simulates the sport of hang gliding or the like, largely in an entertainment based system. The simulation system of the present invention may alternatively be used for training purposes as well.
As disclosed, the simulation system comprises a mechanical support structure for suspending a rider in a harness so as to allow freedom of movement. The rider is suspended to face a visual display, over a movable control bar coupled to the mechanical support structure. By maneuvering the control bar, riders may view the results of their actions as by a simulated display. The visual display is coupled to the control bar to receive electrical signals indicative of the movements initiated by the riders as they maneuver through a programmed environment. The visual display, which is a stereoscopic and collimated virtual image display provides "pupil forming" images of positional states of the hang glider to the riders, at a fixed point of reference relative to the visual display. The fixed point of reference is provided by limiting movement of the rider's head relative to the visual display, as for example with a head rest disposed directly above the viewing area of the visual display.
The stereoscopic and collimated virtual image display facilitates a very wide field of view and accommodates the rider's eyes to focus at infinity. Thus, the programmed environment or imagery appears to be in the distance and, not only is the binocular convergence of the rider's eyes parallel, but the focus of the eyes is relaxed as if collimated.